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Posted

As the title says hello all, a bit of history about me.. I am fairly practical and mechanically minded and have been building custom motorcycles and cars on and off for the last 35 years but have never worked on anything as delicate as a watch movement.. The thing is I have a few manual wind and automatic watches and thought it was about time I learnt something about them ( have been doing some research on the web and watching some of Marks videos for a while )

I have since been having a conversation with my father and told him I was going to purchase some old / non working watches to take apart and see what they are all about when he produced his old seiko diashock 17 jewel watch ( I think I can remember him wearing it when I was a kid ) he told me " it was a good watch in it's time but hasn't worked for years " so I could have it to take apart.. After popping the case apart I took the counter weight that winds the automatic winding up ( sorry I don't know it's correct name ) cleaned of some muck and put it back together, gave it a gentle shake and it wound up ok and started working ( and has been going ok since ) I have found a few problems with it ( as far as I can tell ) and they are as follows.

1. when adjusting the time I have to keep constant outward pressure on the winder with my finger nails or the hands don't move.

2. The weight that moves to wind the watch has some play in it ( I think ) as it looks like it has rubbed against the inside of the watch ( it seems to still wind ok though )

3. The crystal is badly scratched and has a crack ( I would imaging I could still find a replacement )

The casing has cleaned up ok and the dial face has age related patina but look nice.. I would love to put it all back with it working correctly and give it back to my father but would like to know if there is a cure for the time adjusting problem and the bit of play in the automatic winding mechanism.. Or is it a case of it's not really worth spending any time on..

Thanks for looking, Steve.

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Posted

Welcome aboard Steve, and thank you for an insight into your background.

I'm not an expert in Seiko watches, although I have serviced a few. The problem with setting the watch sounds like a broken setting lever spring. This spring ensures that the clutch snaps in and out when the stem is pushed and pulled. To access this (keyless work), you will have to remove the hands and dial. Have a look at this well presented walkthough of a Seiko movement by Lawson, although mot exactly the same, it will let you see what you will have to do.

Regarding the wobbly rotor, you will have to find a replacement bearing or plate complete with bearing. As the watch is old, you may have to source second hand parts.

One of our members Blacklab specialises in Seiko and I'm sure will be able to offer excellent advice.

Posted

Dear Steve,

 

Welcome! You'll find this is one of the best places on the internet and full of helpful info.

 

Here are a few things that might help you along:

 

For your rotor scraping issues, check a few things first. It appears that someone at some point has tried to take the rotor off with a screwdriver that didn't quite fit as there are a few intention scratches on the face of the rotor. The first thing I'd do is get a sharp, well fitting screwdriver (even if you have to sharpen one from the garage) and take the rotor off and clean the rotor and screw really well. If the screw isn't fully seated because of a little residual goo etc. it won't rotate at a right angle and will scrape. When you have the rotor off, look at it up close and make sure it hasn't been bent. Seat it back with the screw and tighten well. Also make sure the movement and face are sitting perfectly in the case (ie if there is a small amount of funk preventing things from properly fitting, the movement and rotor will be closer to the caseback than it should be).

 

If there are issues with the screw or rotor that can't be salvaged, try looking for a replacement on ebay or google using "Seiko 7625 rotor." In the back of your mind you can take solace that even if something really goes wrong and the movement is a goner, there are lots of replacement parts or whole movements available for a watch like this with sentimental value.

 

For your hands adjustment issue, the first thing I'd try is replacing the winding stem. Again, these parts are very easy to come by on ebay ("Seiko 7625 winding stem") and quite cheap. Sometimes simple aging and use can make the fine angles on the stem round over time. I once read in a forum post that watch manufacturers designed winding stems to be of softer metals than the parts they interacted with so that if a replacement needed to be made from years of wear, it would be the stem that is replaced (which is pretty easy) rather than the deep parts. I'm not sure if this is correct but it seems to make sense. I'd be interested to hear what the pros here think.

 

For the crystal, definitely get a replacement. Replacing a watch crystal is one of the most satisfying parts of touching up a watch. It appears the watch has a domed non-glass/sapphire crystal and there are a number available on ebay (search "seiko 7625 crystal" and make sure the result lists 7625-1990 as a compatable model). For the actual how to of replacing a domed crystal like this there are a lot of good videos on youtube:

 

 

I would resist the urge to try and modify in a sapphire crystal. I've made that trip and it was much harder than I thought involving some risky (in my hands) case work.

 

I hope that helps, if you google "restoration-7625-seiko-sportsmatic-march-1969" a somewhat similar thread that might give some more info is there as well.

 

In the interest of full disclosure, I am a true amateur at all of this. If one of the professional guys tells you something different, listen to them,

 

Mute

Posted

Thanks every one for the information, it now gives me a place to start... I think I will try and source whatever is needed and put it back together for my father to use once again..

Posted

Welcome to the forum Steve. Seiko rotors (oscillating weights as Seiko call them) & their bearings are a bit of a pain to say the least, being prone to an early death with the tell-tale scraping sound as the weight eats the movement. 6XXX & earlier 7XXX series had the bearing (Seiko part no. 821820) fitted under a circular plate on the bridge held by 3 screws, so far I have had to cannibalise other movements to replace these as they are no longer available. Later 7XXX series up to the present 7S26 the bearing is part of the rotor & can be replaced by a 7S26 rotor, although unfortunately these are being phased out too.

Posted

Welcome to the forum Steve. Seiko rotors (oscillating weights as Seiko call them) & their bearings are a bit of a pain to say the least, being prone to an early death with the tell-tale scraping sound as the weight eats the movement. 6XXX & earlier 7XXX series had the bearing (Seiko part no. 821820) fitted under a circular plate on the bridge held by 3 screws, so far I have had to cannibalise other movements to replace these as they are no longer available. Later 7XXX series up to the present 7S26 the bearing is part of the rotor & can be replaced by a 7S26 rotor, although unfortunately these are being phased out too.

Thanks for the useful information .

Posted (edited)

An assembly tech sheet for a Seiko 7S26 , NOT your 7625 , but they will be similar in the setting lever components layout .

 

Also from Ranfft's watch movements webpage , Info on a 7625D ...yours is 7625A . The difference may be the jewel count or the next generation , etc. [ Taken from Ranfft's Watch Movements ... You can Google the page and in the search box type "Seiko 7625"....

 

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Seiko 7625 D.html

Edited by ricardopalamino
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